gg.cor produces incorrect plots

[rohitrrj]

Thank you for the great package.
I have noticed the implementation of gg.cor produces incorrect results!
eg. When you provide gene1 = "TCF7" and gene2 = "IFNG", it will produce an identical plot as gene1 = "IFNG" and gene2 = "TCF7"

I believe this is a result of using "subset" function which sorts the data frame and you "hard-code" the columns used for x and y in the ggplot function.